without

英 /wɪˈðaʊt/ 　美 /wɪˈðaʊt/

prep. 没有；不带；不与……一起not having, using, or being accompanied by someone or something
prep. 未做某事not doing the action mentioned

I left the house without my keys this morning.

今天早上我出门时没带钥匙。

Cities cannot achieve lasting reductions in air pollution without investing in reliable public transport.

如果不投资可靠的公共交通，城市就无法持久地减少空气污染。

搭配

without doubt 毫无疑问without permission 未经许可without delay 立即；毫不拖延without saying a word 一言不发地

without 是介词，后接名词、代词或动词-ing。

反义 with